advocate

nouns

a person who pleads for a cause or propounds an idea
advocate, advocator, exponent, proponent
a lawyer who pleads cases in court
advocate, counsel, counsellor, counselor, counselor-at-law, pleader

verbs

push for something
"The travel agent recommended strongly that we not travel on Thanksgiving Day"
advocate, recommend, urge
speak, plead, or argue in favor of
"The doctor advocated a smoking ban in the entire house"
advocate, preach
is derived from
advocator
is derived from
advocacy